Burglar alarm



Feb. 20, 1923.

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' INVENTOR.

- ATTORNEY. P

E. L. RYCRAFT. l

BURGLAR ALARM. FILED SEPT. 15. 1922.

Patented Feb. 20, 1923.

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EVA L. RYGRAF'I, 0F DENVER, COLORADO.

' BURGLAR ALARM.

, Application filed September 15, 1922. Serial No. 588,436.:

To all whom it may concern:

Be 1t known that I, EVA L. RYORAFT, a

citizen of the U nited'States, residing at Denver, in the county ofDenver and State of in my United States Letters Patent #903,888

of NovemberlY, 1908. v

The device consists of a spring actuated clock-movement which throughthe medium ofa spring clamp is attached to a window casing in thechannel ofthe lower sash.

The clock movement operates a going mounted in juxtaposition thereto andit is controlled by a pivoted member which frictionally'engages with theupper sash.

The improvements above referred to reside mainly in changes in the formand arrangement of the controlling member, which simplify theconstruction and increase the efficiency of the device, and theyfurthermore reside in details of construction as will fully appear inthe course of the following de scription.

An embodiment of my invention has been illustrated in the accompanyingdrawings in the various views of which like parts are similarlydesignated and in which- Figure 1 represents a partially broken frontelevation of my improved? {burglar alarm in its operative positionrelative to the upper and lower sashes of a window casing;

Figure 2, a sectional side elevation of the device;

Figure 3, a section taken on the line 83, Figure 1; and

Figure 4:, a section along the line 4-4,

Figure 1. drawn to an exaggerated scale.

Referring more specifically to the drawings, the reference character 5designates a window casing having spaced channels 6 and 7 for the up anddownward movement of upper and lower sashes 8 and 9 of a window ofconventional construction.

The improved burglar alarm consists of a base plate 10 which at itslower end is connected to aU-shaped spring clamp 12 by means ofwhich thedevice is held in the channel of the lower window sash as shown inFigures 1 and 8 of the drawings.

The plate has at its upper end a pair of alined arms'l3 which guideandsteady the correspondingly grooved upper ends of the U-clamp, and whichare provided with heads 13 to limit the Outward movement of the same.- 7I v The clamp has-at its'ends forwardly proj ecting thumbpieces12" bymeans of which its normally converging members operative dow sash.

are" brought together to place the device in its position in the channelof the win- The clock movement above referred to is in its entiretymounted upon a circular plate 14 which is rigidly attached to the baseplate.

It consists of an escapement which controls the operative action of acoiled spring 15 upon the hammer16' of a gong l7 which is mounted upon aspider 18 attached to the plate 14:.

' The spindle l9 the'clock movement projects through a central apertureof the gong and is provided exteriorly of the same, with a knurled head20 by means of which the spring is wound.

The controlling member of the clock movement consists of a pawl or dog21 on the arm of a bell crank 22 which is pivotally mounted in anoutwardly projecting tubular bearing 23 on the base plate.

The crank carries a tubular housing 24: in which a contact-piece 25 ismounted to move longitudinally against the resistance of a spring.

The contact piece consists of a plunger which is fitted forreciprocation in a bore of the housing and which has a head for theengagement of a coiled spring in an enlarged chamber of the same.

A nut 27 at an end of the plunger limits its outward motion by expansionof the spring, and a tip 28 of resilient material in a recess at the endof its head, engages in practice with the upper window sash as shown inthe drawing.

The alarm in its operative position isheld in the channel of the lowersash by expansion of the U-shaped clamp which in order to place thedevice, was momentarily compressed by means of its forwardly projectingthumb-pieces. V

The lower end of the clamp engages with or extends slightly above thelower window sash, and the tip of the contact piece is in 1 frictionalengagement with the upper sash and thereby holds the pawl on the bellcrank in mesh with the wheel of the escapement. I

After the spring of the movement has been wound by means of the head 20of its spindle, the device positioned as hereinabove described, Willbeactuated to sound the gong by either an upward movement of the lowersash or a downward motion of the-upper one, it being evident that ineither case the bell crank will be turned about its pivot so as torelease its pawl from the teeth of the escape wheel.

Having thus described my invention, what I claim and desire to secure byLetters Patentis:

1. A burglar alarm comprising a base, a clamp on the base for securingit in a sash channel of a window frame, a gong'on the base,spring-actuated mechanism adapted to sound the gong, a pivoted member onthe base adapted to restrain the mechanism, and

a resilient contact piece on the member adapted to frictionally engagewith a sashin another channel of the frame.

2. A burglar alarm comprising a base, a

clamp on thebasefor securing it in a sash channel of, a window frame, agong on the base,spring-actuated mechanism adapted to sound the gong, apivoted member on the base adapted to restrain the mechanism, a

housing on the member, a spring-urged plunger movable in the housingand-adapted to engage with a sash in another channelof the frame.

3. A burglar alarm comprising a base, a clamp on the base for securingit in a sash channel of a window frame, a gong on the base,spring-actuated mechanism adapted to sound the gong, and including anescape wheel, a pivoted pawl on the base, engaging with the wheel, and aspring-urged contact piece mounted in connection with the pawl adaptedto engage with a sash in another channel of the frame.

4. A burglar alarm comprising a base, a clamp on the base for securingit in a sashchannel of a window frame, a gong on the base,spring-actuated mechanism adapted to sound the gong, and including anescape wheel, a bell crank pivoted on the base and having a pawlengaging with the Wheel, and a spring-urged contact piece on the bellcrank, adapted to engage with a sash in another channel of the frame.

In testimony whereof I have afiixed my signature.

EVA L. RYCRAFT.

